8. Experimental Investigations on SCC with Indigenously Developed Geopolymer Aggregates

The excessive use of natural aggregates is having an adverse effect on the environment and raises major environmental issues; hence, an attempt has been made to develop artificial aggregates. These artificial aggregates are made from using GGBS, sodium hydroxide and sodium silicate. This paper focuses on the fresh, hardened and durability properties of self-compacting concrete with artificial geopolymer aggregates (GPAs) as partial to full replacement of natural aggregates. Mix design was carried out with varying content of GPA (0–100%) and cements contents (300, 350 and 400 kg/m³). Flow, passing ability and segregation resistance were found to increase when 400 kg of cement and 100% replacement of 10 mm GPA is used as compared to crushed gravel. However, the compressive strength was found to be marginally less with the increase in aggregate size. After examining, the properties of SCC with geopolymer aggregate of size varying from 10 to 20 mm are used in casting of the sleepers. The sleepers were precast in Malu sleeper yard, Birur, Karnataka, and subjected to bending, electrical resistivity and durability tests. The results from static bending test showed that the resistance load of a sleeper with 50% of 6 M aggregate is 238 and 230 kN for conventional concrete. Electrical resistivity and durability of a sleeper with 6 M was found better than conventional concrete sleeper. The prediction of self-compacting concrete properties with artificial geopolymer aggregate and natural aggregate was investigated by using MATLAB.